In a catastrophic aviation event involving a downed aircraft, a flight recorder is one of the most useful tools for investigators to piece together the crucial moments leading up to the aircraft accident or incident to determine the cause of the crash. One type of flight recorder is a cockpit voice recorder (CVR) that records the audio environment of the flight deck of an aircraft. A CVR records conversations in the cockpit and communications between the cockpit crew and others such as air traffic control personnel on the ground. Another type of flight recorder is a flight data recorder that records information about the electronic and mechanical equipment of the aircraft. A flight data recorder records information such as flight parameters (e.g., altitude, speed, etc.) of the aircraft, and may include engine performance data, or other information useful in assisting investigators to determine the cause of a crash.
A flight recorder is designed to withstand high impact forces and high temperatures such that the flight recorder is likely to survive the conditions of a crash. However, while a flight recorder is designed to survive a crash, there is still a probability that the flight recorder may not survive if the crash conditions are extreme enough. Furthermore, a flight recorder is only useful if the flight recorder can be located after a crash. For example, when an aircraft crashes at sea and is submerged in water, locating the flight recorder affixed to the downed aircraft can take weeks to months, and even years, and can be costly in terms of the amount of money and time spent in locating the flight recorder. Even when an aircraft crashes on land, it may take significant effort and time to locate the flight recorder, for example, when the crash site is an unfamiliar or rough terrain. Such delay in locating the flight recorder not only frustrates investigators but can also risk the safety of other aircrafts. For example, when a catastrophic aviation event is caused by a design flaw in an aircraft component, the delay in identifying the problematic component can risk the safety of other aircrafts that employ the same type of aircraft component.
Flight recorders on aircraft collect at least 25 hours of flight data and two hours of cockpit voice information. This information is stored within a crash-survivable memory module which can be retrieved in the event of a crash or as part of regular maintenance. The Achilles'heel of typical “fixed” recorders is that they must be located in order to retrieve the data and in many cases cannot be found after a catastrophic incident. Deployable flight recorders solve this problem by separating from the aircraft during a crash thereby avoiding the extreme conditions of the impact zone and allowing for easier recovery.
Conventional deployable flight recorders rely on pyrotechnic or chemical systems to eject the flight recorder from the aircraft. Such systems require use of explosive devices to trigger the deployment in the event of a crash. For example, a low power explosive may be used to push the flight recorder off the aircraft. However, use of such systems can be a safety risk for installers and maintenance workers. Additionally, the presence of explosive devices on the aircraft may cause a safety concern among the passengers. In some cases, transportation regulations may not allow the use of explosive devices on an aircraft.
Embodiments of the invention address these and other problems, individually and collectively.